1. Field of the Invention
The present invention relates to a magnification measuring mark for semiconductor devices, and more particularly to a magnification measuring mark adapted to measure the magnification of a pattern which is transferred to a wafer by use of a stepper in the fabrication of DRAM's, SRAM's or LCD's.
2. Description of the Prior Art
In the fabrication of semiconductor devices, pattern overlap measuring marks are widely used to measure the overlay of a pattern mask layer disposed over another pattern mask layer.
Factors used to measure a pattern overlay include a misalignment value between two overlaying pattern layers, a pattern magnification value and a pattern rotation value.
Overlay measuring marks are mainly adapted to measure a misalignment value, thereby correcting a pattern overlay. It is very complex to calculate pattern magnification and rotation values. Moreover, it is impossible to know data used in the process of calculating those pattern magnification and rotation values.
For this reason, it is difficult for persons engaged in the fabrication of semiconductor devices to accurately know magnification values of all patterns formed in the fabrication of semiconductor devices.